Pore Fluid Latent Heat

The pore fluid latent heat material model defines the changes in internal energy during phase change of the pore fluid material.

The latent heat is assumed to be released over a range of temperatures from a lower (solidus) temperature to an upper (liquidus) temperature.

Smooth Latent Heat Transition

Optionally, you may specify a smooth transition from solidus to liquidus temperature using

U θ = ( L H )   ξ 3 ⁢ ( 10 − 15 ξ + 6 ξ 2 ) ⁢         f o r ⁢         θ S ≤ θ ≤ θ L ,
where U θ is the internal energy, L H is the latent heat, and ξ = ( θ − θ S ) ( θ L − θ S ) . The above function is such that the first and second derivatives of U θ are zero at θ S and θ L . The definition is intended to ramp up from one value to another. In addition, you can extend the solidus-liquidus temperature interval using a scale factor, f , as follows:
θ S _ n e w = 1 2 [ θ S + θ L − ( θ L − θ S )   . ⁢   f ]
θ L _ n e w = 1 2 [ θ S + θ L + ( θ L − θ S )   . ⁢   f ]

Input Data Description
Latent heat Latent heat per unit mass.
Solidus temperature Low end of the temperature range within which the phase changes occurs.
Liquidus temperature High end of the temperature range within which the phase changes occurs.
Scale factor Scale factor to extend solidus-liquidus interval. The default value is 1.0.

 

See Also
Elastic Behavior of Porous Materials